http://www.nfldraftbible.com/All-Access-Football/first_round_wideouts_a_recipe_for_disaster.html Good read
IMO there are so many 1st round WR draft busts b/c teams fall in love with the measureables. I think that the traits that are most predictive of success are route running and hands. They are both predictive for the same reasons. They can both be indicators of work ethic. In particular route running. In most college practices there is only a limited amount of time that can be dedicated to practicing route running. A receiver who runs excellent routes most likely had to put in a great deal of work outside of practice to achieve that. I've never seen anybody who was a great route runner without putting in a ton of extra work. A natural hand catcher could also be the product of extra work but there are some people who are naturals. If you have those two traits in a package that is 6' 200lbs and has 4.5 speed then you have a 1st round WR. You give him 4.4 or better speed then he's a top 5 pick. The mistake teams make is that the draft tends to push players with great measureables up. As the article says it wouldn’t be far-fetched to say that the sheer athleticism found in this group is unmatched. So teams see those measureables and forget the importance of route running (and the work ethic it indicates). The result is that WRs tend to get drafted too high and articles like this appear saying that drafting WRs is particularly risky. It's not. What's risky is not knowing what to look for and drafting on measureables alone. In this draft, we have a great example. Darius Heyward-Bey has incredible measureables and is a very poor route runner. He has shot up the board and is now a first round pick. I've seen at least one mock that had him going in the top 10. As a prospect I would rate him as a third round pick. He may overcome his lack of route running prowess and actually become a great WR but the fact that he hasn't learned yet makes him a very risky selection. IMO far to risky to be considered a first round pick.
One thing that I always wonder about with 1st round busts is how much of a factor was coaching. It seems to me that a significant number of these busts are drafted by teams who are regularly bad teams. So for me the question is, are they busts primarily because they didn't get the teaching they needed from the coaches? Or was everyone just plain wrong and their skill set just didn't translate to the NFL?
I think you have to trust your scouts and front office. I don't think a players position means they are going to be a bust, if your front office, scouting department, and coaching staff think a player is the best on the board at your slot you take them. The draft is risky, thats what makes it do much fun as a fan to watch and follow over the years.